1. Field of the Invention
This invention relates to water sample collecting devices.
2. Description of the Prior Art
The present invention is directed toward an improvement in a water sample device shown in U.S. Pat. Nos. 4,091,676 and 4,037,477 to the same inventor as in the subject invention. Referring to FIGS. 14 and 16 in U.S. Pat. No. 4,091,676, a stub shaft extends through a bottle so as to engage a groove on a ball valve so that when a pair of pulleys are rotated the ball valves are rotated from an open position to a closed position and viceversa. The ball valve was mounted on a free floating valve seat with an outer peripheral shoulder which sealingly engages a peripheral shoulder formed in the interior of the bottle.
The problem with the prior art design described above is that the bottle is formed from standard PVC pipe which is readily available at low cost. This PVC pipe has inner and outer diameters that can vary substantially. As a result, the valve seat can find itself in a variety of offset positions in that it must have an outer diameter dimensioned to accommodate the varying inner diameter of the tubular bottle. Unrestrained, the ball valve will center itself and settle into a good water tight engagement of the valve seats, despite the variations in the diameter of the bottle. However, the stub shaft greatly restrains the movement of the ball valve. For example, when the shaft is fully extended into the groove, movement is prevented in a direction toward the shaft and in a direction toward the walls of the groove. As a result of this restrained freedom of movement of the ball valve, sometimes an imperfect off-center positioning of the ball valve results in water leaks between the ball valve and the valve seat. The present invention is directed toward overcoming this problem.